A new animal model has become available in the Bedlington terrier. This dog inherits a chronic progressive hepatitis leading to its death from hepatic failure and hemolytic anemia when it is 6-8 years old. Hardy and associates have discovered that this familial liver disease is associated with very high liver copper levels. Whether this is comparable to human Wilson's disease or not is unknown. Preliminary studies indicate that not only is copper metabolism abnormal in the Bedlingtons, it is unusual (for mammals) in normal dogs. A thorough study of normal dogs will precede that of the Bedlingtons. This will include absorption and excretion of copper, the nature of serum copper proteins, metabolism of radiocopper, effect of established and novel decoppering drugs, and serial histologic examinations of the liver.